ACS Chemical Neuroscience
May 30, 2018
Bruce K. Cassels, Patricio Sáez-briones
84 citations
Mescaline, a cactus alkaloid, has been used for over 6000 years, primarily in peyote (Lophophora williamsii) and wachuma cacti. Spanish colonizers banned these plants, but use persisted and spread. By the late 1800s, mescaline was isolated and shown to cause psychedelic effects; its structure was synthesized in 1929. Its effects mainly involve 5-HT2A serotonin receptor agonism, though it also binds to 5-HT1A and α2A receptors. Most mescaline is excreted unchanged in urine, and its metabolites do not contribute to psychedelic effects. Low potency led to less recreational use compared to more potent analogues. Renewed therapeutic interest may clarify differences among classic hallucinogens.
Behavioral neuroscience
October 1, 2010
David Quinteros-Muñoz, Patricio Sáez-briones, Gabriela Díaz-véliz et al.
12 citations
MDMA (ecstasy) produces a unique set of behavioral effects in rats that distinguishes it from both stimulants and hallucinogens. In a series of behavioral tests, the effects of MDMA at various doses were compared with those of methamphetamine (a stimulant) and DOI (a hallucinogen). The behavioral profiles allowed researchers to differentiate MDMA from these other drugs. Additionally, four structural analogues of MDMA were tested, but none exactly replicated MDMA's profile, some resembling the stimulant or hallucinogen instead. This highlights MDMA's distinct pharmacological identity as an entactogen.
Front Pharmacol
February 28, 2019
Patricio Sáez-briones, Vicente Castro-Castillo, Gabriela Díaz-véliz et al.
4 citations
The psychomotor stimulation and pro-social effects of MDMA (ecstasy) in rats are eliminated by aromatic bromination, a chemical modification that replaces a hydrogen atom on the aromatic ring with bromine. The brominated compound retains affinity for the serotonin transporter (SERT), indicating that binding to SERT alone is insufficient to produce these behavioral effects. The findings suggest that other mechanisms beyond SERT binding are necessary for MDMA's characteristic psychomotor and pro-social actions.
Frontiers in pharmacology
January 1, 2026
Patricio Sáez-briones, Amanda Silva-Rodríguez, Michelle Morales-Vidal et al.
MDMA (Ecstasy) suppressed helping behavior in adult male rats at doses of 5 mg/kg and 10 mg/kg, fully eliminating the behavior, while lower doses (1 mg/kg and 0.5 mg/kg) caused partial inhibition only after the rats switched roles. The lowest dose (0.25 mg/kg) had no effect. Electrophysiological recordings showed that MDMA reinforced long-term depression in the nucleus accumbens core and increased long-term potentiation in the anterior cingulate cortex, with the latter depending on serotonin and oxytocin. These neuroplastic effects align with mechanisms thought to promote prosocial behavior, yet the drug disrupted helping behavior, suggesting MDMA may impair neural processes essential for executing helping actions without reducing the willingness to help.